555S-552A bearing: complete specifications & equivalents
The 555S-552A is a ANSI ABMA 19.2 radial bearing sized 57.15 x 123.825 x 38.1 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 57.15 mm |
| Outer diameter D | 123.825 mm |
| Width B | 38.1 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 175 kN |
| Basic static load rating C0 | 216 kN |
| Limiting speed (mechanical) | 3000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2170 g |
| Manufacturer designation | NTN 4T-555S/552A |
| Standard | ANSI ABMA 19.2 |
| Catalog version | NTN 2203E 2026-09-25 |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN 2203E 2026-09-25) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN 2203E 2026-09-25); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & 4t-inch-series range
| Bore d | 2.25 in |
|---|---|
| Outer diameter D | 4.875 in |
| Width B | 1.5 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 33.3 mm |
| Smallest bore in 4t-inch-series | 12.7 mm |
| Largest outer diameter in 4t-inch-series | 260 mm |
| Width range across 4t-inch-series | 10.998–77.788 mm |
| Bore position in 4t-inch-series (smallest first) | 72 of 148 |
| Bore above smallest 4t-inch-series size | 44.45 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 555S | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 555S-552A model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-555S/552A denotes the pure-numeric inch family of NTN inch tapered roller bearings — cone 555S and cup 552A delivered as a matched, separable pair of 57.15 mm bore and 123.825 mm outside diameter. Unlike ISO 355 metric numbers, this ABMA code does not encode the bore arithmetically: 555S identifies the cone of 57.15 mm (2.25 in) bore by catalogue lookup, and 552A fixes the 123.825 mm OD. Grease relubrication at the 3,000 r/min limiting speed targets the cone-rib contact; sustaining 4,100 r/min needs an oil supply directed at the large roller ends. Housing fitment sequence for 4T-555S/552A: press the 552A cup square into the 123.825 mm seat first, then bring the 555S cone (on its 57.15 mm shaft) into adjustment — the two references are separate engineering parts that happen to ship as one set. Back-to-back (O) and face-to-face (X) arrangements of two 4T-555S/552A sets react differently to shaft bending; choose the orientation for the moment load before locking shoulder geometry.
Typical equipment & failure modes
Common applications
- paper-machine and calender roll supports
- off-highway and forestry machine axles
- marine winch and deck-machinery shafts
- crusher and screening-plant eccentric shafts
Known failure patterns
- rib-face scoring when the thrust share of the combined load exceeds what the cone rib of this size carries
- preload loss and noise after one bearing of the adjusted pair is replaced without resetting end play
- false brinelling on a stationary pair exposed to vibration during transport or standby
- cage damage from a mounting blow transmitted through the roller complement
- edge loading when shaft deflection exceeds the few arc-minutes an adjusted pair tolerates
Selection pitfalls — read before you substitute
- Mount the 57.15 mm cone by induction heating (max 120 °C) and the 123.825 mm cup with a press sleeve; at 2170 g a cocked ring brinells the raceway directly.
- The pure-numeric inch family at 57.15 mm bore (123.825×38.1 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 555S/552A reference at purchase.
- Grease packs must leave free volume inside the 38.1 mm-wide set; over-greasing a pair churning near the oil-band speed of 4,100 r/min raises temperature and destroys the setting.
- Fit selection follows the rotating ring: a rotating cone on a 57.15 mm shaft takes a k5/m5 seat, and a rotating cup reverses the logic — decide from the load diagram, not from habit.
- An unloaded 4T-555S/552A near 3,000 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded high-speed pairs.
- The 175/216 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-555S/552A; internal geometry legitimately differs between inch-series makers, so re-verify ratings, adjustment and the exact cone/cup references before substituting another brand on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 4T-555S/552A?
4T-555S/552A is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 57.15 mm bore (2.25 in), 123.825 mm outside diameter and 38.1 mm assembled width T (4.875 × 1.5 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 175 kN, C0 216 kN, grease limiting speed 3,000 r/min, oil speed 4,100 r/min, mass about 2170 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-555S/552A interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 555S cone or the 552A cup can be replaced by an identical reference from NTN or another ABMA-dimensioned maker. Pairing the cone with a different cup reference is a different catalogue row: OD, assembled T and the 175/216 kN ratings change with the cup.
What is the difference between 4T-555S/552A and a metric ISO 355 tapered bearing?
4T-555S/552A follows the ABMA inch boundary plan with cone/cup references; ISO 355 bearings use metric dimension-series numbers (302, 322, …). Even where a metric size looks close to 57.15×123.825×38.1 mm, the envelopes and contact angles differ — the two systems are not drop-in interchangeable; check every boundary value before substituting.
What does the 4T prefix on 4T-555S/552A mean?
4T is NTN's tapered roller bearing quality mark, stamped on cone and cup in the factory. It identifies NTN's 4T programme and is not a dimension or variant code, so interchange lists quote the bare 555S/552A references; the 4T spelling is retained among this page's search aliases.
Why does 4T-555S/552A list two speeds, 3,000 and 4,100 r/min?
The lower figure, 3,000 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 4T-555S/552A at 4,100 r/min because oil removes rib-contact heat better. Real limits still depend on pair adjustment, oil flow and cooling.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN 2203E 2026-09-25 on 2026-10-01. Read our editorial & correction policy.